You have a 12 or 13-year-old? Ask them what they know about “the world as a global community, and the political, economic, environmental and social implications of this”. Ask them about “the diversity of national, regional, religious and ethnic identities in the United Kingdom”. Share with them their “reflections on the process of participating”. Then ask yourself what this toxic mix of political correctness and new age mysticism has to do with education.

The quotations are from David Blunkett’s great legacy as education secretary: a new national curriculum subject, citizenship. Something, he felt, had to be done to counter the yob culture and develop a sense of responsibility and national identity. As the then chief inspector of schools in England and Wales, I agreed. Of course, who wouldn’t? But who in their right mind would waste time on this sort of twaddle?

Some 90% of 15 to 24-year-olds do not know that King John signed the Magna Carta. Under a quarter can name either the most recent monarch to abdicate (Edward VIII) or the opposing sides in the wars of the roses (York and Lancaster). Citizenship in primary schools is meant to teach children to “feel positive about themselves” by, for example, “producing personal diaries, profiles and portfolios of achievements”. Not, you note, through mastering new knowledge and pushing back the frontiers of what they believe they can achieve.

The national curriculum should be a straightforward statement of what children need to be taught in the traditional subjects of the school timetable — English, maths, science, history, art, and so on. That was what the original national curriculum more or less was.

But even when it was formulated, back in the late 1980s, it was a battle. Some educationists resented the very idea that subjects could be taught separately and what mattered was the “seamless web of knowledge”. Others attacked the focus on subject knowledge, saying children needed to be taught “cross curricular” skills such as “problem solving” which were far more important than boring facts.

The battle was, ultimately, for the soul of state education and since 1997 those of us who think that a national curriculum should encapsulate worthwhile knowledge have suffered some pretty comprehensive defeats. That is why Michael Howard is right to call for a review of the national curriculum, and why I have agreed to undertake that rethink if the Conservatives win the election.

Most of us would probably agree that some time in the school week should be spent on sex and careers education. What, though, of cramming in “education for sustainable development”, the teaching of “financial capability”, “enterprise and entrepreneurial skills”, the provision of “work-related learning”, the promotion of “spiritual, moral, social and cultural development”? Oh yes, and the odd period for the banal pieties of Blunkett’s citizenship curriculum.

It can’t be done. These are the unworkable aspirations of politicians who will never have to deliver in the classroom. Five-year-olds are expected to develop “entrepreneurial characteristics of tenacity, independence, innovation, imagination, risk-taking, creativity, intuition and leadership”.

I don’t know about you, but 53 years on I am feeling more than a little inadequate. I would like teachers to teach children to read, and I rather suspect that they might have more success if the national curriculum had some clear focus on phonics, shown in study after study to be the key to reading.

Under the current system children are expected to “select and apply skills, tactics and compositional ideas” in physical education. In history what matters is not the story of the past, but the skills of the historian. They must be taught “to recognise that the past is represented and interpreted in different ways, and to give reasons for this”. At seven, 11 or 14, even when most children do not have the shakiest grasp on the facts of what happened when?

And so it goes on. The rationale for the geography order makes passing reference to “developing knowledge of places” and teaching about maps, but suggests that the subject is important because it is “a focus within the curriculum for understanding and resolving issues about the environment and sustainable development”. David Bell, the current chief inspector of schools, agrees. “Geography,” he said recently, “enables us to understand change, conflict, and the key issues which impact on our lives today and will affect our futures tomorrow.” His inspectors are delighted by a new GCSE course that is not “overloaded with content”. Students are encouraged to submit poems and posters that register their feelings about these pressing contemporary concerns.

I want children to leave school knowing something. It is the depth and breadth of their understanding, not the precocity of their feeling that matters. The emphasis today is increasingly on the latter. We tell our children less and less and expect them to tell us at an earlier and earlier age what they think about massively complex issues.

The reality, of course, is that they reflect back to us what we have taught them to think and feel. The national curriculum has become a vehicle for indoctrination and in its present form it should be abolished. The only alternative is a review that returns to what matters: the teaching of worthwhile knowledge.